A team of architectural historians created a replica of a Nazi gas chamber that is now on display at the 15th International Venice Architectural Biennale, Wired.comreported.

The reconstruction, called “The Evidence Room,” comes with a full-scale gas column, door and a gas-tight hatch. Robert Jan van Pelt, an architectural historian at Canada’s University of Waterloo, along with other professors and students from the university, built the exhibit to work with the Biennale’s theme of “Reporting from the Front.”

“It is a profound experience for all of us,” said van Pelt in a statement, “and, in design terms, a radical, unprecedented investigation into the possibility to represent something unrepresentable: the architectural evidence of a factory of death.”

The design for “The Evidence Room” was taken from actual evidence Van Pelt presented in court when he was called to defend writer and historian Deborah Lipstadt, after Holocaust denier David Irving sued her for libel in 1996.

Lipstadt’s 1994 book, Denying the Holocaust: The Growing Assault on Truth and Memory, attacked revisionists, included Irving, who allegedly denied or understated the killing of 6 million Jews during World War II. Lipstadt and her publishers, Penguin Books, denied libeling Irving by calling him “a Holocaust denier.”

To fight the lawsuit, Lipstadt needed to prove that the Holocaust did in fact happen, Wired.com reported. When the court asked Van Pelt to present evidence proving that Nazis used the concentration camps for genocidal purposes, he showed blueprints and letters left behind by the architects who built the crematoria.

After considering the case for almost four weeks, a judge ruled against Irving, according to The Guardian.

The Venice Architectural Biennale takes place from May 28 to November 27.